The Checklist Manifesto_ How to Get Things Right - Atul Gawande [52]
One more aviation checklist story, this one relatively recent. The incident occurred on January 17, 2008, as British Airways Flight 38 approached London from Beijing after almost eleven hours in the air with 152 people aboard. The Boeing 777 was making its final descent into Heathrow airport. It was just past noon. Clouds were thin and scattered. Visibility was more than six miles. The wind was light, and the temperature was mild despite the season—50 degrees Fahrenheit. The flight had been completely uneventful to this point.
Then, at two miles from the airport, 720 feet over a residential neighborhood, just when the plane should have accelerated slightly to level off its descent, the engines gave out. First the right engine rolled back to minimal power, then the left. The copilot was at the controls for the landing, and however much he tried to increase thrust, he got nothing from the engines. For no apparent reason, the plane had gone eerily silent.
He extended the wing flaps to make the plane glide as much as possible and to try to hold it on its original line of approach. But the aircraft was losing forward speed too quickly. The plane had become a 350,000-pound stone falling out of the air. Crash investigators with Britain’s Air Accidents Investigation Branch later determined that it was falling twenty-three feet per second. At impact, almost a quarter mile short of the runway, the plane was calculated to be moving at 124 miles per hour.
Only by sheer luck was no one killed, either on board or on the ground. The plane narrowly missed crashing through the roofs of nearby homes. Passengers in cars on the perimeter road around Heathrow saw the plane coming down and thought they were about to be killed. Through a coincidence of international significance, one of those cars was carrying British prime minister Gordon Brown to his plane for his first official visit to China. “It was just yards above our heads, almost skimming a lamppost as the plane came in very fast and very, very low,” an aide traveling with the prime minister told London’s Daily Mirror.
The aircraft hit a grassy field just beyond the perimeter road with what a witness described as “an enormous bang.” The nose wheels collapsed on impact. The right main landing gear separated from the aircraft, and its two right front wheels broke away, struck the right rear fuselage, and penetrated through the passenger compartment at rows 29 and 30. The left main landing gear pushed up through the wing. Fourteen hundred liters of jet fuel came pouring out. Witnesses saw sparks, but somehow the fuel did not ignite. Although the aircraft was totaled by the blunt force of the crash, the passengers emerged mostly unharmed—the plane had gone into a thousand-foot ground slide that slowed its momentum and tempered the impact. Only a dozen or so passengers required hospitalization. The worst injury was a broken leg.
Investigators from the AAIB were on the scene within an hour trying to piece together what had happened. Their initial reports, published one month and then four months after the crash, were documents of frustration. They removed the engines, fuel system, and data recorders and took them apart piece by piece. Yet they found no engine defects whatsoever. The data download showed that the fuel flow to the engines had reduced for some reason, but inspection of the fuel feed lines with a boroscope—a long fiberoptic videoscope—showed no defects or obstructions. Tests of the valves and wiring that controlled fuel flow showed they had all functioned properly. The fuel tanks contained no debris that could have blocked the fuel lines.
Attention therefore turned to the fuel itself. Tests showed it to be